Valve gear for explosion and internal combustion engines working on any cycle



Oct. 29, 1935. V

ALVE GEAR FOR ENGI J. E. SERSTE 2,019,161 EXPLOSION AND INTERNAL COMBUSTION ON A CYCLE NES WORK Filed Ap 27 7 Sheets-Sheet l Oct. 29, 1935. J E E' 2,019,161

VALVE GEAR FOR EXPLOSION AND INTERNAL COMBUSTION ENGINES WORKING ON ANY CYCLE Filed Aprll 27. 1954 '7 Sheets-Sheet 2 1W WW M Oct. 29, 1935. V

J. E. SERSTE 2,019,161 ALVE GEAR FOR EXPLOSION AND INTERNAL COMBUSTION ENGI E NES WORK G ON CYCL Filed Ap 3 7 Sheets-Sheet 3 J v L Q 32 W in C 56 J) frwmi? E m fig) O .1

06. 29, 1935. J E E TE 2,019,161

VALVE GEAR FOR EXPLOSION AND INTERNAL COMBUSTION ENGINES WORKING ON ANY CYCLE Filed Aprll 27 1934 '7 sh t -sh t 4 7 Sheets-Sheet 5 CYCLE 34 'JFW,

INTERNAL COMBUSTION G ON ANY J. E SE PLO ON KIN Filed April 27, 19

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VALVE GEAR FOR EXPLOSION AND INTERNAL COMBUSTION ENGINES WORKING ON ANY CYCLE Filed April 27, 1934 '7 Sheets-Sheet 6 Oct. 29, 1935. J. E. SERSTE 2,019,161

VALVE GEAR FOR EXPLOSION AND INTERNAL COMBUSTION ENGINES WORKING ON ANY CYCLE Filed April 27, 1934 '7 Sheets-Sheet Patented Oct. 29, 1935 PATENT OFFIE VALVE GEAR FOR EXPLOSION AND INTER- NAL COMBUSTION ON ANY CYCLE ENGINE S. WORKING Jacques Egide Serst, Laeken-Brussels, Belgium- Application April 27, 1934, Serial No. 722,637 In Belgium May 10, 1933 7 Claims. (Cl. 12375) My present invention relates to valve-gears for internal combustion engines and has for its object to provide an improved valve-gear, wherein the cylinder head is moved partly or totally by means of a rocking device, on which the weight of the various parts of the gear as well as the pressures supported by the latter are balanced totally or partly.

According to the invention the mechanism for uncovering and covering the exhaust and admission ports or either of them comprises two series of parts simultaneously actuated in opposite directions and each forming a force producing opposite effects on the rocking part, in such a way that the weight of each part will be compensated by the other.

The thrust of the pressures produced by compression and expansion will be likewise compensated. Such thrust will act on the parts, the

surfaces of which, taking up the vertical thrust of the pressures, are proportioned to the length of the lever connecting them to the rocking member, so as to secure a perfect balance.

Therefore the effect of the improved valve-gear is to reduce to a minimum the action of the mechanical power, as the latter has now merely to overcome the frictional resistance of the various parts of the gear and inertia thereof.

It will be obvious that for technical or physical reasons the balance may be destroyed so as to charge one arm of the rocking device with a higher pressure than the other.

Broadly stated the piston and its lining sleeve, which together open and close the exhaust and admission-or one of themare actuated by means of rigid links connected to a rocking member and incapable of passing beyond each other in both directions without engaging one or more segments upon their return movements.

Such rigid links are objectionable in that they produce a lateral thrust on the driven members, and the advantage of causing the piston to alternately pass beyond its lining sleeve and viceversa--at least in certain cyclesproduces complications capable of interfering with the operation of the valve-gear.

In order to avoid these objections, my invention also contemplates the provision of means, serving:

(1) To annihilate the lateral thrust on the parts of the valve-gear by the insertion of a toggle device, held in operative position, for instance by means of links or guides; (2) Permit 5; the piston rings to pass beyond its lining sleeve and vice versa without being engaged upon the return movement.

In theaccompanying drawings I have illustrated. by way of non limitative example, a plurality of preferred embodiments of my invention. 5

In these drawings:

Fig. 1 is a vertical transverse section of an exhaust and. admission device for four stroke cycle engines, combined with a rocking device actuated by a set of cams and rollers, the part 10 for controlling the ports being shown as fitted concentrically within each other, and more specially on. line I- -I of Fig-.4.

Fig. 2 is a vertical transverse section of said device. but on line IIII of Fig. 4., 15

Fig. 3 is a vertical transverse section corresponding to Fig. 1 except therocking member being in one end position opposite to the position shown in Fig. 2.

Fig. 4 is a vertical section on the axis of the 20 cam shaft.

Fig. 5 is a similar vertical transverse section as shown in Fig. 1, of an exhaust and admission device for four stroke cycle engines, also combined with a rocking device but actuated by the 5 friction of a set of cams and guides arranged concentrically to the outer bosses of said cams upon the contact of said guides with said cams, whereby any action of the rocking device will be avoided during this period. 30

Fig. 6 is a vertical section of an exhaust and admission device as Fig. 5, section on the axis of the cam shaft corresponding to Fig. 2.

Fig. '7 is a vertical section of an exhaust and admission device as Fig. 5, section on the axis of 35 the cam shaft corresponding to Fig. 3.

Fig. 8 is a vertical transverse section of the axis of the cam shaft with reference to Figs. 5, 6, and 7.

Fig. 9 is a, sectional view of a device for four 40 stroke cycle engines, in which the pistons controlling the exhaust and admission are independent from each other, said pistons covering simultaneously the exhaust and admission ports.

Fig. 10 is a sectional view of the device as illustrated in Fig. 9, one of the pistons covering the admission ports, the exhaust port being uncovered.

Fig. 11 is. a sectional view of the device as illustrated in Fig. 9', one of the pistons covering the exhaust port, the admission port. being uncovered.

Fig. 12 is a sectional view of the device for two stroke cycle enginesin which the parts controlling the exhaust and. admissionare engaged concentrically within each other, the rocking movement being controlled by means of a toggle lever device, shown in one of its extreme positions.

Fig. 13 shows the toggle lever as illustrated in Fig. 12, in its other extreme position.

Fig. 14 is a vertical axial section on line IIIIII of Fig. 15 and showing an engine cylinder with an improved valve-gear.

Fig. 15 is a vertical section on a plane at right angle according to Fig. 14 and on line IV-IV of such Fig. 14.

Fig. 16 is a horizontal section on line V-V of Fig. 15.

Fig. 17 shows diagrammatically the same engine cylinder with the valve-gear in an equilibrium position.

Fig. 18 shows the same engine with the valvegear in one of its extreme positions, and

Fig. 19 this valve-gear in its other extreme position.

Fig. 20 shows another ar angement of the retaining links.

Fig. 21 is a vertical section on line VIIIVIII of Fig. 22, showing details of the protecting ring of the piston and the usual piston ring, this arrangement serving to prevent the piston rings from engaging the lining sleeve upon their return movement.

Fig. 22 is a horizontal section on line IXIX of Fig. 21.

Fig. 23 shows a plan view of the blank from which the closed protecting ring of the piston is made.

Fig. 24 is a sectional view of said ring on line X-X of Fig. 22.

Figs. 25 and 26 show in sections recessed piston rings.

1 wish it to be understood that any one of the driving or operating devices hereinafter described may be applied to any desired valve-gear controlling the ports of an engine.

In the examples illustrated the rocking device comprises a rocking part A, journaled in stationary bearings B, constituting the centres of the entire system of the valve-gear and supporting the stress resulting from the thrust of the cams, the suction of the admission (in the four stroke cycle) and the pressure of the compression and expansion.

A distributing piston C, enclosed within a lining sleeve D, or a set of pistons C D are each connected to each of the opposite sides of the rocker A by means of links E, F.

Ports l and 2 for the four stroke cycle and l for the two stroke cycle are provided in the cylinder G for the exhaust and admission in the four stroke cycle, and indifferently for the exhaust or admission in the two stroke cycle, the exhaust or admission being adapted to be efiected at the end of the piston stroke.

The sleeves D are provided with ports 3, adapted to register on one hand with the ports I in the cylinder G and on the other hand with the races 1, 8, 9, cooperating with rollers I0 and II or guides l2, l3 and 14, so as to cause the rocker to be rocked or locked.

The number of the parts composing the whole gear may be increased or decreased according to circumstances. The rocker may also be actuated indirectly through the agency of toggle'levers, links or any other intermediate part.

During the compression and expansion, the vertical pressure supported by the piston C and sleeve D, or by the pistons C and D is proportionally equal to the surfaces upon which such pressure is exerted, so that by adjusting the length of each arm of the rocker with relation to the differences of pressure received by them, it will be possible to obtain the desired degree of balance.

The complete covering of the exhaust and admission ports (which may be termed dead centre) is held closed during the compression and expansion because of the balance of the pressures on piston and ring on the lever arms. (Figs. 1, 5, 9 and 12).

At the beginning of the exhaust the rocker will be rocked by its operating device to uncover the exhaust ports, either by the registering of the various ports (Figs. 2, 6, and 13) or by the proper movement of the single obturator (Fig. 10).

'Whilst for closing the exhaust 1n the two stroke cycle engine, the operating parts are moved to the dead centre (Fig. 12), in the four stroke cycle engine the dead centre will be rapidly passed and by a movement opposite to the first one the admission will be uncovered (Figs. 3, 7, and 11) and then brought to the dead centre (Figs. 1, 5, and 9).

' According to the embodiments illustrated in Figs. 14 to 26, the sleeve D is connected to the rocker A by means of a double set of links F-J, pivotally connected at 20 to each other as well as to the retaining links N, the other end of which is pivotally connected to the stationary axle 22, whilst the piston C is connected to the rocker A through the agency of another double set of links E-e, the links of which are pivotally connected at 2| to each other as well as to the retaining link M, the other end of which is pivotally connected to the stationary axle 23.

The result of this arrangement which is a toggle joint is that at the moment the thrust of the gases of the compression or combustion is etfected on the member C and D, the links 1 and 6 will be held in the axis of the piston C and sleeve D by the links N and M, whereby any lateral thrust will be avoided on said members. The admission and exhaust movements are accomplished along a very short arc, through which the connections 20 and 21 are moved with the axles 22 and 23 as centres. The links E and F operate'in the same way as in the arrangements described with reference to Figs. 1 to 13.

A similar eiTect may be obtained by guiding the links e and f or their pivotal connections 28 and 2| in vertical guides.

On the other hand, in order to avoid any interference between the piston and sleeve thereof upon their return movements, I provide the piston with a closed ring 3! (Figs. 21 to 24) having apertures 32 extending close to one of its rims and leaving braces 33 between them. The ends of said braces 33 enclose the offset in the single or first piston ring 34, so that the piston ring and braces do not extend beyond each other. A removable ring may be inserted between the difierent elements, and in order to increase the number of piston rings it will be sufi'icient to cause oifsets thereof to engage each other as shown in Fig. 25 (rings 34 and 34").

Owing to this arrangement, at the moment the piston C is moved inwardly into the cylinder, the piston ring 34 may be completely disengaged from the sleeve D without being capable of increasing its diameter beyond that imposed by the braces 33. The latter, in spite of their slight release at the moment they leave the sleeve, will bring the diameter of the piston ring back to the exact bore of the sleeve D in proportion as said piston ring will be moved nearer to said sleeve. It will be obvious that the ring 3| and the piston ring or rings 34 may be housed within the sleeve D and act on the piston by contraction, and no more by expansion as in the arrangement just described.

The invention having been described by way of example only, it will be obvious that changes or modifications may be made in the details of construction without departing from the scope of the invention.

I claim:

1. In a valve-gear for internal combustion engines having a cylinder with a combustion chamber with an exhaust and admission port, the combination of a ring, said ring enclosing a piston forming the parts serving to cover and uncover the exhaust and admission ports, a rocking member to which said ring and piston are respectively connected, these parts having balanced surfaces in area exposed to the pressure in the combustion chamber substantially as described.

2. In a valve-gear for internal combustion engines having a cylinder with a combustion chamber with an exhaust and admission port, the combination of a ring, said ring enclosing a piston forming the parts serving to cover and uncover the exhaust and admission ports, a rockingmember to which said parts are respectively connected, said rocking member having movement in opposite directions, and connecting links transmitting the movements of said rocking-member to said parts, substantially as described.

3. In a valve-gear for internal combustion engines having a cylinder with a combustion chamber with an exhaust and admission port, the combination of a ring, said ring enclosing a piston forming the parts serving to cover and uncover the exhaust and admission ports, a rockingmember to which said parts are connected, said rocking member having movementin opposite directions, connecting links transmitting the movements of said rocking-member tosaid parts and a set of cams driving said rocking-member in both directions, substantially as described.

4. In a valve-gear for internal combustion engines having a cylinder with a combustion chamber with an exhaust and admission port, the combination of a ring, said ring enclosing a piston forming the parts serving to cover and uncover the exhaust and admission ports, a rocking-member to which said parts are connected, said rocking-member having movement in opposite directions, connecting links transmitting the movements of said rocking-member in both directions, said rocking-member being provided with 5 rollers and cams contacting said rollers, substantially as described.

5. In a valve-gear for internal combustion engines having a cylinder with a combustion chamber with an exhaust and admission port, the combination of a ring, said ring enclosing a piston forming the parts serving to cover and uncover the exhaust and admission ports, a rockingmember towhich said parts are connected said rocking-member having movement in opposite directions, connecting links transmitting the movements of said rocking-member to said parts,

a set of cams driving the rocking-member in both directions, said rocking-member being provided with rollers, toggle-leversprovided between the connecting links and said parts for the purpose of changing substantially the lateral thrust of said connecting links to an axial thrust, substantially as described.

6. In a valve-gear for internal combustion engines having a cylinder with a combustion chamber with an exhaust and admission port, the combination of a pair of parts concentrically arranged and serving to cover and uncover the exhaust and admission ports, a rocking-member to which said parts are connected, said rocking-member having rocking and reciprocating movements, connecting links transmitting the movements of said rocking-member to said parts, a set of cams driving the rocking-member in its movements, said rocking-member being provided with rollers, toggle levers between connecting links and said parts, for the purpose of changing the lateral thrust of connecting links to an axial thrust, and means holding said toggle-levers in operative positions, substantially as described.

7. In a valve-gear for internal combustion engines, the combination of a cylinder having a combustion chamber in the head thereof with exhaust and admission ports, concentric parts consisting in av distributing piston and a movable sleeve surrounding said piston in the ported combustion head of said cylinder, these parts having balanced surfaces exposed to the combustion chamber pressures, a rocking-member actuating said piston and sleeve toobtain rocking and reciprocating movements, connecting links transmitting the movements of said rocking-member to said parts, toggle-levers between said connecting links and these parts, for the purpose of changing the lateral thrust of said connecting connecting links to an axial thrust, and links pivotally connected to said toggle-levers and to a stationary part of the engine for holding the toggle levers in operative positions, substantially as described.

JACQUES EGIDE SERSTE. 

